method_demo.rb

# A simple class in Ruby
class Human
  def introduce
    "Hi, I am a #{self.class.name}"
  end
end

Human.ancestors
#=> [Human, Object, Kernel, BasicObject]
# Object is present in Human class's ancestor tree.
# Hence #method of Object can be used on instances of Human class

Human.new.method(:introduce)
#=> #<Method: Human#introduce>
# Method object for Human's instance method #introduce

method(:puts)
#=> #<Method: main.puts> 
# Method object for #puts method.

[1,2,3,4].method(:length)
#=> #<Method: Array#length>
# Method object for Array's instance method #length